| In recent years, the inertial technology has been the important research point in national defense all over the world. The fiber optic gyro is a new kind of gyro with unique entirely solid state and is based on the effect of Sagnac. With its advantage of having latent and best function/price ratio and easily interface to the digital signal processing device, it has been highly valued and noticed by the countries all over the world. Now it has been an ideal inertial instrument of a new generation with middle and low precision used to the strap-down inertial navigation system.One of the key techniques in inertial technology is how to quickly and independently ascertaining the carrier's initial direction, witch is said inertial north-seeking technology. This article commences from the FOG's principle and its function index, first giving an sample static north-seeking scheme and its test method, then exploring the plan design and mathematic model of north-seeking system on vehicle based on one FOG and two accelerators, last using the digital signal processing (DSP) floating chip TMS320VC33 design the system's software and hardware.To solve the most difficult and important problem that the FOG's drift is too big to use in north-seeking system, it first analyses the source of FOG's noise and its character, synthetically gives the FOG's signal drift mathematic model, then uses the Fourier transform to analyze the frequency character of the FOG's output signal, last attempts to apply the wavelet analysis to the signal processing of the FOG. Computer simulation shows that compared with traditional IIR filter, wavelet analysis has the absolute advantage in FOG signal processing, it can eliminate FOG's random drift greatly and the processing result is very good. |
